6.85% of the population for whom poverty status is determined in Keystone, SD (23 out of 336 people) live below the poverty line, a number that is lower than the national average of 12.5%. The largest demographic living in poverty are Males 25 - 34, followed by Females < 5 and then Males 6 - 11.

The most common racial or ethnic group living below the poverty line in Keystone, SD is White, followed by Black and Native American.

The Census Bureau uses a set of money income thresholds that vary by family size and composition to determine who classifies as impoverished. If a family's total income is less than the family's threshold than that family and every individual in it is considered to be living in poverty.